ci: add coverage.yml

Author: indaco

.github/workflows/coverage.yml

@@ -0,0 +1,33 @@
+name: Test Coverage
+
+on:
+  push:
+    branches: [main]
+  workflow_dispatch:
+
+jobs:
+  coverage:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v5
+
+      - name: Set up Go
+        uses: actions/setup-go@v6
+        with:
+          go-version: '1.25'
+          check-latest: true
+
+      - name: Install Go modules
+        run: go mod download
+
+      - name: Verify dependencies
+        run: go mod verify
+
+      - name: Run go test
+        run: go test -count=1 -timeout 30s $(go list ./... | grep -Ev 'internal/testhelpers') -covermode=atomic -coverprofile=coverage.txt
+
+      - name: Upload coverage reports to Codecov
+        uses: codecov/codecov-action@v5
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}